Method of pumping wells drilled below water



March 28, 1967 B, G ABLE 3,311,063

METHOD OF PUMPING WELLS DRILLED 'BELOW WATER,

iled Dec. 10, 1965 392 Sheets-Sheet 1 a. 11 I 3 gg xaf LINE PRODUCTIONas-X f N VEN 7'02. Do/vam/v B. Gene/.5

" QM #W March 28, 1967 Filed Dec. 10, 1965 D. B. GRABLE 3,311,063

METHOD OF PUMPING WELLS DRILLED BELDW WATER 2 Sheets-Sheet B ens/Iv;

PUMP CONTROL fm/wroe. Dana vq/v B. 02921.5

3,311,063 METHOD OF PUMPING WELLS DRILLED BELOW WATER Donovan B. Grable,Long Beach, Calif., assignor of onethird to K. L. Bourdo, Phoenix,Ariz., and one-third to C. R. Summers, Houston, Tex.

Filed Dec. 10, 1965, Ser. No. 512,954 12 Claims. (Cl. 103-43) Thisinvention has to do with the pumping of wells drilled beneath water asat offshore locations in the ocean. More particularly, the inventionrelates to novel methods for pumping of such wells by the employment offloated energy for stroking well pumps operated by verticallyreciprocable rod strings.

Offshore wells may be produced using conventional pumps whose strokescan be of considerable length, e.g. around 20 feet and greater, althoughthe invention is not limitative in this respect. Adding to the welldepth the water depth above, considerable energy is required for pumpingelevation of production to the water surface.

The present invention is predicated upon the derivation of such energyat least in part, by economical means employing a pump actuating bargeconnected to the rod string and operating in an essentially reciprocallyfloating manner to cause pumping reciprocation of the rod string. Inthis manner it becomes possible to employ the energy of natural watermovements where available, for pumping displacement of the barge, andlargely to limit otherwise powering of the barge to reverse movementsfor which the barge resistance may be reduced, as will apear. p Afurther important feature of the invention is the employment of suchpumping barge for reception and storage of production from the well.Thus the barge may be equipped for oil storage from which the oil may betaken to larger capacity shipping vessels. If desired, the barge mayhave additional facilities for the accommodation or treatment of gasreleased from the well, such for example as an oil-gas separating unitfor the recovery of liquid or liquefiable hydrocarbons in the gas.

In its equipment aspects, the invention contemplates the provision ofappropriate production pipe or tubing extending upwardly from the welland within which the pump rod string extends. The rod string isconnected to the barge by a flexible cable extending thereto from whatmay be termed a guide location, in relation to which the barge may havereciprocating movement in different radial directions.

A further feature and object of the invention involves the exertion ofcounter loading of the pump and string so as to control or minimize thepumping power required of the barge under either water motion or motordriven influence.

All the features and objects of the invention, as well as the details ofan illustrative embodiment, will be more fully understood from thefollowing description of the accompanying drawing, in which:

FIG. 1 is a general view, diagrammatic in parts, showing an illustrativewell installation and associated pumping barge;

FIG. 2 is a plan view of the barge assembly; and

FIG. 3 is an enlarged showing of the wire line guide and controlassembly as viewed from line 33 of FIG. 1.

In reference first to the generalities of the system, an oil well isshown to be located in the formation 11 underlying a body of water 12 asat at an off-shore ocean location where the height of the wellsuperstructure generally indicated at 13, will be predeterminedaccordingly. At its surface the water normally may be in a state ofcurrent flow, causing displacement of the barge generally United StatesPatent 07 3,311,063 Patented Mar. 28, 1967 indicated at 14, or the watercondition may be relatively quiescent, requiring greater powereddisplacement of the barge.

The well 10 is shown to comprise a usual combination of a casing 15having a conventional head 16, and containing tubing 17 which receivesproduction entering through the casing perforations into the bottom ofthe tubing, the oil being elevated by a pumb 19 operated by verticalreciprocation of the attached rod string 20. The casing head 16 mounts aconventional tubular riser 21 that may accommodate a usual blowoutpreventor 22 and gas seal packer 23. Within its upper extent the riser21 receives the tubular support 24 having a wire line control headgenerally indicated at 25, and which establishes the guide location fora line or cable 26 connected at 27 to the upper end of the rod string 20and extending to a connection at 28 with the barge 29. The support 24preferably is mounted for vertical adjustment above the riser 21 in asuitable manner as typified by a releasable clamp ring 30 at the top ofthe riser. Any suitable means, merely typified by guy cables 31, may beemployed to support and laterally stabilize the superstructure 13.

The wire line control head maybe of usual design comprising, e.g. 'alateral arm 32 extending from collar 33 which swivels on the support 24,the arm inturn carrying a post 34 which mounts the cable sheave 35. Thusthe cable 26 extends about the sheave to the barge and the sheavetogether with its'mounting bodily swivels about the support 24 inaccordance with the radial direction of the cable 20 running to thebarge. Generally it is preferred to maintain the head assembly 25 nearthe surface of the" water, and where the water level is subject toperiodic changes, the elevation of the assembly 25 may be adjustedaccordingly.

The barge 29 is shown diagrammatically to carry oil storage facilitiesas within the hold of the barge or a tankage 37 into which oil elevatedby the pump into riser 21 is delivered by way of line 38. The barge maycarry an added facility 39 for the reception of gas from the wellthrough line 40, the facility 39 being e.g.' conventional equipment forseparating or recovering liquid or condensible hydrocarbons from thegas.

In the broad contemplation of the invention, the barge 29 may beequipped with any suitable means operable to enhance displacement of thebarge by such water currents or flow as may exist at the well location.As illustrative, such means generally indicated at 42 may comprise apair of vanes 43 pivoted at 44 to swing between the solid line projectedpositions and contracted broken line positions of FIG. 2 in response tosuitable actuation as by piston 45 operating within cylinder 46 andpivoted at 47 to the vane arms 48. Hydraulic fluid is delivered to thecylinder 46 for the piston and vane actuation from pump 49 through line50 under control of four-way valve 51 which also governs the cylinderreturn flow through line 52. The valve 51 may be associated with anappropriate remote control 53. The pump 49 is shown to be powered by thebarge engine 54 which also operates reversibly to drive propeller 55which powers the barge in its pumping displacement.

Referring particularly to FIG. 3, the assembly 25 is shown to includealso a drum 56 about which is spooled cable 57 supporting acounterweight 58, the latter being of sufficient mass or Weight tosubstantially counterbalance the weight of the pump rod string 20 sothat the pumping load or pull to be exerted by the barge willessentially be that required for elevation of the pumped liquid columnwith only that excess attributable to the weight of the rod string,sufficient to allow the string to lower when the barge pull is released.Force transmission between the barge and counterweight 58 through theas- C; sembly 25 requires in effect keying of the sheave 35 and spool 56to the shaft S. To anticipate variance in the transmission by reason ofconsequential slippage of the cable 26 on the sheave 35, that section ofthe cable as between the locations 60 and 59 which reciprocally travelsthe sheave, may be replaced by chain section 20a with the sheavesprocketed to have non-slipping retention of the chain.

In considering the operation of the system, the pump 19 may be assumedto operate at considerable stroke upon by the water flow in thedirection of its movement.

Approaching the limit of the pump upstroke the vanes may be retractedand the barge then reversely powered by its propeller 55. In the absenceof natural water movement, the barge may be reciprocally powered Withinthe v limits of the pump stroke by reversely driving the propeller.

I claim:

1; The method of operating a pump withina well below a body .of water byvertical reciprocation of a rod string connected to the pump, thatcomprises connecting liquid separating facility and gas is conductedfrom the Well to said facility.

4. The method of claim 1, in which the barge is motor driven in at leastone direction of its reciprocal movements.

5. The method of claim 4, in which the barge is displaced in onedirection by movement of the water and is motor driven in a generallyopposite direction.

6. The method of claim 1, including also the step of variably elevatingsaid guide location in accordance with changes in the water level.

7. The method of claim 1, in which the rod string is counterweighted andthe barge elevates the counterweighted string.

the rod string with a barge on the water by a flexible line leading tothe barge from a guide location, and reciprocally moving the barge inrelation to said location to vertically reciprocate the rod string.

8. The method of claim 7, in which the barge is equipped for oil storageand oil is pumped by said pump into the barge.

9. The method of claim 9, in which the barge has a liquid-gas separatingfacility and gas is conducted from the Well to said facility.

10. The method of claim 4, in which the barge is motor driven in atleast one direction of its reciprocal movements.

11. The method of claim 8, in which the barge is displaced in onedirection by movement of the water and is motor driven in a generallyopposite direction.

12. The method of claim 11, including also the step of variablyelevating said guide location in accordance with changes in the waterlevel.

References Cited bythe Examiner UNITED STATES PATENTS ROBERT M. WALKER,Primary Examiner.

1. THE METHOD OF OPERATING A PUMP WITHIN A WELL BELOW A BODY OF WATER BYVERTICAL RECIPROCATION OF A ROD STRING CONNECTED TO THE PUMP, THATCOMPRISES CONNECTING THE ROD STRING WITH A BARGE ON THE WATER BY AFLEXIBLE LINE